; Lisp code placed in ROM
; return a list containing all of the arguments
+(def (quote list) (lexpr (l) l))
-(set (quote list) (lexpr (l) l))
+(def (quote def!)
+ (macro (name value rest)
+ (list
+ def
+ (list quote name)
+ value)
+ )
+ )
- ;
- ; Define a variable without returning the value
- ; Useful when defining functions to avoid
- ; having lots of output generated
- ;
+(begin
+ (def! append
+ (lexpr (args)
+ ((lambda (append-list append-lists)
+ (set! append-list
+ (lambda (a b)
+ (cond ((null? a) b)
+ (else (cons (car a) (append-list (cdr a) b)))
+ )
+ )
+ )
+ (set! append-lists
+ (lambda (lists)
+ (cond ((null? lists) lists)
+ ((null? (cdr lists)) (car lists))
+ (else (append-list (car lists) (append-lists (cdr lists))))
+ )
+ )
+ )
+ (append-lists args)
+ ) () ())
+ )
+ )
+ 'append)
-(setq def (macro (name val rest)
- (list
- 'progn
- (list
- 'set
- (list 'quote name)
- val)
- (list 'quote name)
- )
- )
- )
+(append '(a b c) '(d e f) '(g h i))
+
+ ; boolean operators
+
+(begin
+ (def! or
+ (macro (l)
+ (def! _or
+ (lambda (l)
+ (cond ((null? l) #f)
+ ((null? (cdr l))
+ (car l))
+ (else
+ (list
+ cond
+ (list
+ (car l))
+ (list
+ 'else
+ (_or (cdr l))
+ )
+ )
+ )
+ )
+ )
+ )
+ (_or l)))
+ 'or)
+
+ ; execute to resolve macros
+
+(or #f #t)
+
+(begin
+ (def! and
+ (macro (l)
+ (def! _and
+ (lambda (l)
+ (cond ((null? l) #t)
+ ((null? (cdr l))
+ (car l))
+ (else
+ (list
+ cond
+ (list
+ (car l)
+ (_and (cdr l))
+ )
+ )
+ )
+ )
+ )
+ )
+ (_and l)))
+ 'and)
+
+ ; execute to resolve macros
+(and #t #f)
+
+(begin
+ (def! quasiquote
+ (macro (x rest)
+ (def! constant?
+ ; A constant value is either a pair starting with quote,
+ ; or anything which is neither a pair nor a symbol
+
+ (lambda (exp)
+ (cond ((pair? exp)
+ (eq? (car exp) 'quote)
+ )
+ (else
+ (not (symbol? exp))
+ )
+ )
+ )
+ )
+ (def! combine-skeletons
+ (lambda (left right exp)
+ (cond
+ ((and (constant? left) (constant? right))
+ (cond ((and (eqv? (eval left) (car exp))
+ (eqv? (eval right) (cdr exp)))
+ (list 'quote exp)
+ )
+ (else
+ (list 'quote (cons (eval left) (eval right)))
+ )
+ )
+ )
+ ((null? right)
+ (list 'list left)
+ )
+ ((and (pair? right) (eq? (car right) 'list))
+ (cons 'list (cons left (cdr right)))
+ )
+ (else
+ (list 'cons left right)
+ )
+ )
+ )
+ )
+
+ (def! expand-quasiquote
+ (lambda (exp nesting)
+ (cond
+
+ ; non cons -- constants
+ ; themselves, others are
+ ; quoted
+
+ ((not (pair? exp))
+ (cond ((constant? exp)
+ exp
+ )
+ (else
+ (list 'quote exp)
+ )
+ )
+ )
+
+ ; check for an unquote exp and
+ ; add the param unquoted
+
+ ((and (eq? (car exp) 'unquote) (= (length exp) 2))
+ (cond ((= nesting 0)
+ (car (cdr exp))
+ )
+ (else
+ (combine-skeletons ''unquote
+ (expand-quasiquote (cdr exp) (- nesting 1))
+ exp))
+ )
+ )
+
+ ; nested quasi-quote --
+ ; construct the right
+ ; expression
+
+ ((and (eq? (car exp) 'quasiquote) (= (length exp) 2))
+ (combine-skeletons ''quasiquote
+ (expand-quasiquote (cdr exp) (+ nesting 1))
+ exp))
+
+ ; check for an
+ ; unquote-splicing member,
+ ; compute the expansion of the
+ ; value and append the rest of
+ ; the quasiquote result to it
+
+ ((and (pair? (car exp))
+ (eq? (car (car exp)) 'unquote-splicing)
+ (= (length (car exp)) 2))
+ (cond ((= nesting 0)
+ (list 'append (car (cdr (car exp)))
+ (expand-quasiquote (cdr exp) nesting))
+ )
+ (else
+ (combine-skeletons (expand-quasiquote (car exp) (- nesting 1))
+ (expand-quasiquote (cdr exp) nesting)
+ exp))
+ )
+ )
+
+ ; for other lists, just glue
+ ; the expansion of the first
+ ; element to the expansion of
+ ; the rest of the list
+
+ (else (combine-skeletons (expand-quasiquote (car exp) nesting)
+ (expand-quasiquote (cdr exp) nesting)
+ exp)
+ )
+ )
+ )
+ )
+ (expand-quasiquote x 0)
+ )
+ )
+ 'quasiquote)
;
- ; A slightly more convenient form
- ; for defining lambdas.
+ ; Define a variable without returning the value
+ ; Useful when defining functions to avoid
+ ; having lots of output generated.
;
- ; (defun <name> (<params>) s-exprs)
+ ; Also accepts the alternate
+ ; form for defining lambdas of
+ ; (define (name x y z) sexprs ...)
;
-(def defun (macro (name args exprs)
- (list
- def
- name
- (list
- 'lambda
- args
- (cond ((cdr exprs)
- (cons progn exprs))
- ((car exprs))
- )
+(def! define
+ (macro (first rest)
+ ; check for alternate lambda definition form
+
+ (cond ((list? first)
+ (set! rest
+ (append
+ (list
+ 'lambda
+ (cdr first))
+ rest))
+ (set! first (car first))
+ )
+ (else
+ (set! rest (car rest))
)
)
- )
- )
+ `(begin
+ (def (quote ,first) ,rest)
+ (quote ,first))
+ )
+ )
+
; basic list accessors
+(define (caar l) (car (car l)))
-(defun cadr (l) (car (cdr l)))
+(define (cadr l) (car (cdr l)))
-(defun caddr (l) (car (cdr (cdr l))))
+(define (cdar l) (cdr (car l)))
-(defun nth (list n)
- (cond ((= n 0) (car list))
- ((nth (cdr list) (1- n)))
- )
+(define (caddr l) (car (cdr (cdr l))))
+
+(define (list-tail x k)
+ (if (zero? k)
+ x
+ (list-tail (cdr x (- k 1)))
+ )
+ )
+
+(define (list-ref x k)
+ (car (list-tail x k))
)
+ ; (if <condition> <if-true>)
+ ; (if <condition> <if-true> <if-false)
+
+(define if
+ (macro (test args)
+ (cond ((null? (cdr args))
+ `(cond (,test ,(car args)))
+ )
+ (else
+ `(cond (,test ,(car args))
+ (else ,(cadr args)))
+ )
+ )
+ )
+ )
+
+(if (> 3 2) 'yes)
+(if (> 3 2) 'yes 'no)
+(if (> 2 3) 'no 'yes)
+(if (> 2 3) 'no)
+
; simple math operators
-(defun 1+ (x) (+ x 1))
-(defun 1- (x) (- x 1))
+(define zero? (macro (value rest) `(eq? ,value 0)))
- ; boolean operators
+(zero? 1)
+(zero? 0)
+(zero? "hello")
+
+(define positive? (macro (value rest) `(> ,value 0)))
+
+(positive? 12)
+(positive? -12)
+
+(define negative? (macro (value rest) `(< ,value 0)))
+
+(negative? 12)
+(negative? -12)
+
+(define (abs x) (if (>= x 0) x (- x)))
+
+(abs 12)
+(abs -12)
+
+(define max (lexpr (first rest)
+ (while (not (null? rest))
+ (cond ((< first (car rest))
+ (set! first (car rest)))
+ )
+ (set! rest (cdr rest))
+ )
+ first)
+ )
+
+(max 1 2 3)
+(max 3 2 1)
+
+(define min (lexpr (first rest)
+ (while (not (null? rest))
+ (cond ((> first (car rest))
+ (set! first (car rest)))
+ )
+ (set! rest (cdr rest))
+ )
+ first)
+ )
+
+(min 1 2 3)
+(min 3 2 1)
+
+(define (even? x) (zero? (% x 2)))
+
+(even? 2)
+(even? -2)
+(even? 3)
+(even? -1)
+
+(define (odd? x) (not (even? x)))
+
+(odd? 2)
+(odd? -2)
+(odd? 3)
+(odd? -1)
+
+
+ ; define a set of local
+ ; variables all at once and
+ ; then evaluate a list of
+ ; sexprs
+ ;
+ ; (let (var-defines) sexprs)
+ ;
+ ; where var-defines are either
+ ;
+ ; (name value)
+ ;
+ ; or
+ ;
+ ; (name)
+ ;
+ ; e.g.
+ ;
+ ; (let ((x 1) (y)) (set! y (+ x 1)) y)
-(def or (lexpr (l)
- (let ((ret nil))
- (while l
- (cond ((setq ret (car l))
- (setq l nil))
- ((setq l (cdr l)))))
- ret
+(define let
+ (macro (vars exprs)
+ (define (make-names vars)
+ (cond ((not (null? vars))
+ (cons (car (car vars))
+ (make-names (cdr vars))))
+ (else ())
)
- )
- )
+ )
-(def and (lexpr (l)
- (let ((ret t))
- (while l
- (cond ((setq ret (car l))
- (setq l (cdr l)))
- ((setq ret (setq l nil)))
- )
- )
- ret
+ ; the parameters to the lambda is a list
+ ; of nils of the right length
+
+ (define (make-vals vars)
+ (cond ((not (null? vars))
+ (cons (cond ((null? (cdr (car vars))) ())
+ (else
+ (car (cdr (car vars))))
+ )
+ (make-vals (cdr vars))))
+ (else ())
)
- )
+ )
+ ; prepend the set operations
+ ; to the expressions
+
+ ; build the lambda.
+
+ `((lambda ,(make-names vars) ,@exprs) ,@(make-vals vars))
+ )
)
+
+
+(let ((x 1) (y)) (set! y 2) (+ x y))
; define a set of local
- ; variables and then evaluate
- ; a list of sexprs
+ ; variables one at a time and
+ ; then evaluate a list of
+ ; sexprs
;
- ; (let (var-defines) sexprs)
+ ; (let* (var-defines) sexprs)
;
; where var-defines are either
;
;
; e.g.
;
- ; (let ((x 1) (y)) (setq y (+ x 1)) y)
+ ; (let* ((x 1) (y)) (set! y (+ x 1)) y)
-(def let (macro (vars exprs)
- ((lambda (make-names make-exprs make-nils)
- (progn
+(define let*
+ (macro (vars exprs)
;
; make the list of names in the let
;
- (setq make-names (lambda (vars)
- (cond (vars
- (cons (car (car vars))
- (make-names (cdr vars))))
- )
- )
- )
+ (define (make-names vars)
+ (cond ((not (null? vars))
+ (cons (car (car vars))
+ (make-names (cdr vars))))
+ (else ())
+ )
+ )
; the set of expressions is
; the list of set expressions
; pre-pended to the
; expressions to evaluate
- (setq make-exprs (lambda (vars exprs)
- (progn
- (cond (vars (cons
- (list set
- (list quote
- (car (car vars))
- )
- (cadr (car vars))
- )
- (make-exprs (cdr vars) exprs)
- )
- )
- (exprs)
- )
- )
- )
- )
+ (define (make-exprs vars exprs)
+ (cond ((null? vars) exprs)
+ (else
+ (cons
+ (list set
+ (list quote
+ (car (car vars))
+ )
+ (cond ((null? (cdr (car vars))) ())
+ (else (cadr (car vars))))
+ )
+ (make-exprs (cdr vars) exprs)
+ )
+ )
+ )
+ )
; the parameters to the lambda is a list
; of nils of the right length
- (setq make-nils (lambda (vars)
- (cond (vars (cons nil (make-nils (cdr vars))))
- )
- )
- )
- ; prepend the set operations
- ; to the expressions
+ (define (make-nils vars)
+ (cond ((null? vars) ())
+ (else (cons () (make-nils (cdr vars))))
+ )
+ )
+ ; build the lambda.
- (setq exprs (make-exprs vars exprs))
+ `((lambda ,(make-names vars) ,@(make-exprs vars exprs)) ,@(make-nils vars))
+ )
+ )
- ; build the lambda.
+(let* ((x 1) (y x)) (+ x y))
- (cons
- (list
- 'lambda
- (make-names vars)
- (cond ((cdr exprs) (cons 'progn exprs))
- ((car exprs))
+(define when (macro (test l) `(cond (,test ,@l))))
+
+(when #t (write 'when))
+
+(define unless (macro (test l) `(cond ((not ,test) ,@l))))
+
+(unless #f (write 'unless))
+
+(define (reverse list)
+ (let ((result ()))
+ (while (not (null? list))
+ (set! result (cons (car list) result))
+ (set! list (cdr list))
+ )
+ result)
+ )
+
+(reverse '(1 2 3))
+
+(define (list-tail x k)
+ (if (zero? k)
+ x
+ (list-tail (cdr x) (- k 1))))
+
+(list-tail '(1 2 3) 2)
+
+(define (list-ref x k) (car (list-tail x k)))
+
+(list-ref '(1 2 3) 2)
+
+ ; recursive equality
+
+(define (equal? a b)
+ (cond ((eq? a b) #t)
+ ((and (pair? a) (pair? b))
+ (and (equal? (car a) (car b))
+ (equal? (cdr a) (cdr b)))
+ )
+ (else #f)
+ )
+ )
+
+(equal? '(a b c) '(a b c))
+(equal? '(a b c) '(a b b))
+
+(define member (lexpr (obj list test?)
+ (cond ((null? list)
+ #f
)
- )
- (make-nils vars)
+ (else
+ (if (null? test?) (set! test? equal?) (set! test? (car test?)))
+ (if (test? obj (car list))
+ list
+ (member obj (cdr list) test?))
+ )
+ )
)
- )
- )
- ()
- ()
- ()
+ )
+
+(member '(2) '((1) (2) (3)))
+
+(member '(4) '((1) (2) (3)))
+
+(define (memq obj list) (member obj list eq?))
+
+(memq 2 '(1 2 3))
+
+(memq 4 '(1 2 3))
+
+(memq '(2) '((1) (2) (3)))
+
+(define (memv obj list) (member obj list eqv?))
+
+(memv 2 '(1 2 3))
+
+(memv 4 '(1 2 3))
+
+(memv '(2) '((1) (2) (3)))
+
+(define (_assoc obj list test?)
+ (if (null? list)
+ #f
+ (if (test? obj (caar list))
+ (car list)
+ (_assoc obj (cdr list) test?)
+ )
+ )
+ )
+
+(define (assq obj list) (_assoc obj list eq?))
+(define (assv obj list) (_assoc obj list eqv?))
+(define (assoc obj list) (_assoc obj list equal?))
+
+(assq 'a '((a 1) (b 2) (c 3)))
+(assv 'b '((a 1) (b 2) (c 3)))
+(assoc '(c) '((a 1) (b 2) ((c) 3)))
+
+(define char? integer?)
+
+(char? #\q)
+(char? "h")
+
+(define (char-upper-case? c) (<= #\A c #\Z))
+
+(char-upper-case? #\a)
+(char-upper-case? #\B)
+(char-upper-case? #\0)
+(char-upper-case? #\space)
+
+(define (char-lower-case? c) (<= #\a c #\a))
+
+(char-lower-case? #\a)
+(char-lower-case? #\B)
+(char-lower-case? #\0)
+(char-lower-case? #\space)
+
+(define (char-alphabetic? c) (or (char-upper-case? c) (char-lower-case? c)))
+
+(char-alphabetic? #\a)
+(char-alphabetic? #\B)
+(char-alphabetic? #\0)
+(char-alphabetic? #\space)
+
+(define (char-numeric? c) (<= #\0 c #\9))
+
+(char-numeric? #\a)
+(char-numeric? #\B)
+(char-numeric? #\0)
+(char-numeric? #\space)
+
+(define (char-whitespace? c) (or (<= #\tab c #\return) (= #\space c)))
+
+(char-whitespace? #\a)
+(char-whitespace? #\B)
+(char-whitespace? #\0)
+(char-whitespace? #\space)
+
+(define (char->integer c) c)
+(define (integer->char c) char-integer)
+
+(define (char-upcase c) (if (char-lower-case? c) (+ c (- #\A #\a)) c))
+
+(char-upcase #\a)
+(char-upcase #\B)
+(char-upcase #\0)
+(char-upcase #\space)
+
+(define (char-downcase c) (if (char-upper-case? c) (+ c (- #\a #\A)) c))
+
+(char-downcase #\a)
+(char-downcase #\B)
+(char-downcase #\0)
+(char-downcase #\space)
+
+(define string (lexpr (chars) (list->string chars)))
+
+(display "apply\n")
+(apply cons '(a b))
+
+(define map
+ (lexpr (proc lists)
+ (define (args lists)
+ (cond ((null? lists) ())
+ (else
+ (cons (caar lists) (args (cdr lists)))
+ )
)
- )
- )
+ )
+ (define (next lists)
+ (cond ((null? lists) ())
+ (else
+ (cons (cdr (car lists)) (next (cdr lists)))
+ )
+ )
+ )
+ (define (domap lists)
+ (cond ((null? (car lists)) ())
+ (else
+ (cons (apply proc (args lists)) (domap (next lists)))
+ )
+ )
+ )
+ (domap lists)
+ )
+ )
+
+(map cadr '((a b) (d e) (g h)))
+
+(define for-each (lexpr (proc lists)
+ (apply map proc lists)
+ #t))
+
+(for-each display '("hello" " " "world" "\n"))
+
+(define _string-ml (lambda (strings)
+ (if (null? strings) ()
+ (cons (string->list (car strings)) (_string-ml (cdr strings))))))
+
+(define string-map (lexpr (proc strings)
+ (list->string (apply map proc (_string-ml strings))))))
+
+(string-map (lambda (x) (+ 1 x)) "HAL")
+
+(define string-for-each (lexpr (proc strings)
+ (apply for-each proc (_string-ml strings))))
+
+(string-for-each write-char "IBM\n")
+
+(define newline (lambda () (write-char #\newline)))
+
+(newline)
+
+(call-with-current-continuation
+ (lambda (exit)
+ (for-each (lambda (x)
+ (write "test" x)
+ (if (negative? x)
+ (exit x)))
+ '(54 0 37 -3 245 19))
+ #t))
+
+
+ ; `q -> (quote q)
+ ; `(q) -> (append (quote (q)))
+ ; `(a ,(+ 1 2)) -> (append (quote (a)) (list (+ 1 2)))
+ ; `(a ,@(list 1 2 3) -> (append (quote (a)) (list 1 2 3))
- ; run the let macro once to
- ; evaluate all of the internal
- ; macro calls
-(let ((let-param 1)))
+`(hello ,(+ 1 2) ,@(list 1 2 3) `foo)
+
+(define repeat (macro (count rest)
+ `(let ((__count__ ,count))
+ (while (<= 0 (set! __count__ (- __count__ 1))) ,@rest))))
+
+(repeat 2 (write 'hello))
+(repeat 3 (write 'goodbye))
+
+(define case (macro (test l)
+ (let* ((_unarrow
+ ; construct the body of the
+ ; case, dealing with the
+ ; lambda version ( => lambda)
+
+ (lambda (l)
+ (cond ((null? l) l)
+ ((eq? (car l) '=>) `(( ,(cadr l) __key__)))
+ (else l))))
+ (_case (lambda (l)
+
+ ; Build the case elements, which is
+ ; simply a list of cond clauses
+
+ (cond ((null? l) ())
+
+ ; else case
+
+ ((eq? (caar l) 'else)
+ `((else ,@(_unarrow (cdr (car l))))))
+
+ ; regular case
+
+ (else
+ (cons
+ `((eqv? ,(caar l) __key__)
+ ,@(_unarrow (cdr (car l))))
+ (_case (cdr l)))
+ )
+ ))))
+
+ ; now construct the overall
+ ; expression, using a lambda
+ ; to hold the computed value
+ ; of the test expression
+
+ `((lambda (__key__)
+ (cond ,@(_case l))) ,test))))
+
+(case 12 (1 "one") (2 "two") (3 => (lambda (x) (write "the value is" x))) (12 "twelve") (else "else"))
+
+;(define number->string (lexpr (arg opt)
+; (let ((base (if (null? opt) 10 (car opt)))
+ ;
+;
+